In this paper, the phase compositions and the dielectric properties of 3ZnO–2B2O3 glass-ceramic prepared by solid-state method were investigated. The X-ray diffraction patterns show that all sintered samples consist of Zn3B2O6 and α-Zn(BO2)2. The dielectric properties changed significantly with the sintering temperature. After sintering at 650°C for 30 min, the glass-ceramic exhibits optimum dielectric properties: a dielectric constant of 7.5 and a dielectric loss of 0.6 × 10−3 at 10 MHz. The chemical compatibility with Ag electrode under the co-fired process illustrates a potential application in low temperature co-fired ceramic field for the glass-ceramic.